DIVING DELL. 
right hand, fixed at a right angle on an ii’on 
rodj which passed through the side of the 
vessel ; the rod had a crank on its outside, 
•which’ commanded the rudder by means of 
a rod extending from tlie end of the crank 
to a kind of tiller fixed on the left hand of 
the rudder. Raising or depressing the first- 
mentioned tiller, turned the rudder as the 
case required. 
A compass marked with phosphorus, di- 
rected the course both above and under the 
water: and a line and lead sounded tlie 
’ ^ 
depth when necessary. 
The internal shape of the vessel in every 
possible section of it, verged towards an el- 
lipsis as near as the design would allow ; 
but every horizontal section of it, although 
elliptical, was as near to a circle as could 
be admitted. The body of tlie vessel was 
made exceedingly strong ; and to strengthen 
it as much as possible, a firm piece of wood 
was framed parallel to the conjugate dia- 
meter, to prevent the sides from yielding 
to the great pressure of the incumbent wa- 
ter, in deep immersions. This piece of 
wood was also a seat for the operator. 
Every opening was well secured. The 
pumps had two sets of valves. The aper- 
ture at the bottom for admitting water- was 
covered with a plate perforated full of 
holes, to receive the water, and prevent 
any thing from choaking the passage, or 
stopping the valve from shutting. The 
brass valve might likewise be forced into 
its place by a screw if necessary. The air- 
pipes had a kind of hollow sphere fixed 
round the top of each to secure the air- 
pipe vtdves from injury : these hollow 
spheres were perforated full of holes for 
the passage of the air through the pipes : 
within the air-pipes were shutters to secure 
them, should any accident happen to the 
pipes or the valves on tlieir tops. 
Wherever the external apparatus passed 
through the body of the vessel, the Joints 
were round, and formed by brass pipes, 
which were driven into the wood of the 
vessel, the holes through the pipes were 
very exactly made, and the iron rods that 
passed through them were turned in a lathe 
to fit them ; the Joints were also kept full 
of oil to prevent rust and leaking. Parti- 
cul-ar attention was given, to bring every 
part necessary for performing the opera- 
tions, both within and without the vessel, 
before tire operator, and as conveniently as 
could be devised ; so that every thing might 
be found in the dark, except the water- 
gauge and the compass, which were vi- 
sible by the light of the phosphorus, and 
nothing required the operator to turn to 
the right hand or to the left to perform any 
thing necessary. 
The intended object of this vessel was to 
destroy shipping, by the explosion of a ma- 
gazine of gunpowder. In the fore part of 
the brim of the crown of the sub marine 
vessel was a socket, and an iron tube pass- 
ing through the socket; the tube stood up- 
right, and could slide up and down in the 
socket six inches ; at the top of the tube 
was a wood screw, fixed by means of a rod, 
which passed through the tube and screwed 
tbe wood screw fast upon the top of the 
tube ; by pushing the wood screw up against 
the bottom of a ship, and turning it at the 
same time, it would enter the planks j driv- 
ing would also answer the same purpose ; 
when the wood screw was firndy fixed, it 
could 1.3 cast off by unscrewing the rod 
which fixed it upon the top of the tube. 
Behind the sub-marine vessel was a place 
above the rudder for carrying a large pow- 
der magazine ; this was made of two pieces 
of oak timber, large enough when hollowed 
out to contain 150 pounds of powder, with 
the apparatus used in firing it, and was 
secured in its place by a screw turned by 
the operator. A strong piece of rope ex- 
tended from the magazine to the wood 
screw above-mentioned, and was fastened 
to both. When the wood screw was fixed, 
and to be cast off from its tube, the maga- 
zine was to be cast off likewise by unscrew- 
ing it, leaving it haugmg to the wood screw; 
it was lighter than the water, that it m.ight 
rise up against the object, and apply itself 
where fastened. 
Within the magazine was an apparatus 
constructed to run any proposed length of 
time under twelve hours ; when it had run 
out its time it unpinioned a strong lock re- 
sembling a gun-lock, which gave fire to the 
powder. This apparatus was so pinioned 
that it could not possibly move, till by cast- 
ing of!' the magazine from the vessel it was 
set in motion. 
The skilful operator could swim so low 
on the surface of the water, as to approacJi 
very near a ship in the night without fear 
of discovery, and might, if he chose, ap- 
proach the stem or stern above water with 
very little danger. He could sink very 
quickly, keep at any depth he pleased, and 
row a great distance in any direction he 
desired, without coming to the surface ; 
and when he rose to the surface, he could 
soon obtain a fresh supply of air, when, if 
